Yanshan University

About: Yanshan University is a education organization based out in Qinhuangdao, China. It is known for research contribution in the topics: Microstructure & Control theory. The organization has 19544 authors who have published 16904 publications receiving 184378 citations. The organization is also known as: Yānshān dàxué.

Dynamic analysis and driving force optimization of a 5-DOF parallel manipulator with redundant actuation

Abstract: Redundant actuation can improve the performance and ability of parallel manipulator. In order to deal with coordination and distribution of the driving force of the parallel manipulator with redundant actuation and to realize the control strategy based on dynamics, on the basis of the original 5UPS/PRPU parallel manipulator, it increases a drive for the middle PRPU passive constraint branch to make it a redundant actuation branch. It introduces configurations’ redundant types and compositions of 5UPS/PRPU parallel manipulator with redundant actuation, illustrates that the mechanism is redundant actuation from the perspective of degree of freedom and establishes a dynamic model based on Lagrangian method. On the basis of the weighted optimization principle of driving torque, it optimizes the driving torque of the parallel manipulator and calculates the driving force of the redundant driving chain with cutting force. It carries out the simulation by using ADAMS software and proves validity of dynamic model. Finally it detects the dynamic performance of the parallel manipulator by processing experiment of parallel manipulator with redundant actuation and its non-redundant counterpart.

Tunable Fiber Polarization Filter by Filling Different Index Liquids and Gold Wire Into Photonic Crystal Fiber

Abstract: A tunable fiber polarization filter by filling different index liquids into the central hole of photonic crystal fiber (PCF) is proposed and demonstrated. The dispersion characteristics and loss spectra of the polarization filter are evaluated by finite element method (FEM). The gold wires are selectively filled into the cladding air holes of the PCF. When the phase matching condition is satisfied, the liquid-core mode couples to surface plasmon polaritons (SPP) mode intensely. The resonance wavelength varies with the change of the structural parameters and liquids. By adjusting the refractive index of the liquid, we realize the polarization filter at the wavelength of 1.31, 1.49, and 1.55 $\mu$ m, respectively, under the optimized structural parameters. This is the first time to propose the narrowband polarization filter at the communication wavelength of 1.31 $\mu$ m to our best knowledge based on the coupling between liquid-core mode and SPP mode, and the full width half maximum (FWHM) is only 16 nm. The loss of X-polarized mode is 44336 dB/m at $\lambda$ = 1.31 $\mu$ m, and the corresponding loss of Y-polarization mode is 224 dB/m. By comparison, we find the birefringence in our structure is further better than that in conventional structure. High birefringence is helpful to separate the resonance wavelength positions of the two orthogonal polarized modes. The result also reveals that resonance loss becomes small with increasing the distance between liquid core and gold wire.

MAS-Based Energy Management Strategies for a Hybrid Energy Generation System

Abstract: An advanced control scheme for managing a hybrid energy generation system (HEGS) is presented in this paper. A hierarchical management and control architecture based on multi-agent systems (MAS) is discussed. MAS will account for the complex behavior of a hybrid energy supply system. The management and control strategies are implemented through a system of agents based on three tiers. The upper level agents develop overall energy management strategies for a hybrid energy supply system. The middle-level agents integrate coordinated switching controllers. The lower level agents are responsible for dealing with local control strategies. Coordinated switching controllers within the middle-level agents are designed as event-triggered hybrid controllers based on differential hybrid Petri-net (DHPN) models. The operation modes of distributed energy resources (DERs) can smoothly transfer in a coordinated manner due to the coordinated action of the switching controllers according to variation in operating conditions. Finally, simulation results from different scenarios verifying the feasibility of the proposed scheme are offered.